1. Field of the Invention
The present invention relates to a method and apparatus for improving bandwidth efficiency in a computer network. More specifically, this invention pertains to a bandwidth management tool that implements a set of rules for directing network traffic according to current network bandwidth levels.
2. Description of the Related Art
Bandwidth is a critical resource and a key cost for Internet service providers (ISPs) in particular. Reliable bandwidth usage auditing and monitoring is important in two types of Web hostings offered by ISPs, i.e., “co-location” and “dedicated/shared-services. The Internet is a collection of interconnected (public and/or private) networks linked together by a set of standard protocols (such as TCP/IP and HTTP) to form a global, distributed network. As used herein, “Internet” is intended to refer to what is now commonly known as the Internet, it is also intended to encompass variations which may be made in the future, including changes and additions to existing standard protocols.
Bandwidth refers to maximum available bit rate for a specific application. In the context of a communication link of a computer network, bandwidth refers the maximum information rate that may be transmitted through the link. As used herein, the bandwidth capacity of a communication link includes any limitations such as arise from characteristics of servers, routers, and other network devices along a link.
Overuse of available bandwidth is generally undesirable. Although certain latency is inherently associated with any computer network (latency refers to the delay experienced by a packet from the source to destination), when bandwidth usage of a communication link approaches or saturates the bandwidth (capacity) of a communication link, increased latency and/or transmission failure results. Therefore, it is desirable to operate a computer network so as to preserve a margin of excess bandwidth at all times.
Bandwidth is also a commodity that may be assigned a definite economic value. In co-location services, a customer owns a dedicated Web server located at an Internet Service Provider's (ISP's) facility, and purchases Internet bandwidth from the ISP. The ISP buys bandwidth in bulk and resells it to each customer. Bandwidth is typically purchased in blocks. For example, a company may pay a fixed amount for a block of one hundred megabits of bandwidth. When bandwidth usage exceeds this amount, the company either incurs surcharges (in the event that it has acquired the ability to “burst” over the paid amount) or hits a cap, and is unable to serve all of the content that has been requested of it. The former results in undesired extra charges, with the latter results portions of the content being indiscriminately not served.
In dedicated-server service, customers rent dedicated servers that are owned and maintained by the ISP. In shared-server service, customers rent disk space, and share CPU and ETHERNET bandwidth with other website customers on the ISP's equipment. While this provides a low cost service for the customer, it frequently results in an overcrowding of the equipment and long delays or inaccessibility of the sites sharing the server. When the ISP has a clear picture of usage patterns, users can be relocated onto servers that do not clash with other users, or changed to dedicated-server service.
Accordingly, customers and ISP's alike desire accurate auditing, monitoring, and allocation of the bandwidth usage by each Web hosting customer. Current software tools for these tasks are not optimal.
The Web hosting business is becoming increasingly competitive. Customers are demanding guaranteed serviced and accountability for the access bandwidth charges by their ISPs. The customers too desire to monitor their own usage patterns in real time. It is further desirable to provide a guaranteed quality of service to improve customer satisfaction. In addition, unlike hit-rate data provided by other software, bandwidth usage patterns give web site owners a different way for gauging responses to changes in content on their sites.
A prior art pure-software approach to bandwidth management implements a priority-based queuing algorithm completely in UNIX or WINDOWS. These implementations usually have too much operating system overhead and throughput rarely exceeds 1,000 Kb/s. A prior art pure hardware approach implements a control algorithm in logic. But only very simple algorithms are practical, such as packet counting and dropping when a bandwidth limit is reached. These basic approaches can drop too many packets unnecessarily, which results in massive re-transmission on the Internet. Instead of improving throughput, these algorithms may actually degrade the network. A further disadvantages of hardware methods is that new features, e.g., Internet Protocol versions upgrades, generally require replacement of hardware equipment.
Routers are commonly used in the art and typically implement the use of headers and a forwarding table to determine the path in which data packets are sent. Very little filtering of data is done through routers. In fact, most routers do not distinguish between the different types of data being transmitted. Nevertheless, bandwidth management strategies are typically implemented at the router level. In networks where files of various types and sizes are frequently passed, however, these strategies are often inefficient.
Accordingly, it would be desirable to provide a method and apparatus for monitoring and optimizing bandwidth usage.